Conventionally, there has been proposed a four-wheel independent steering and independent braking and driving control which maximizes a grip additional coverage in each of the wheels, that is, minimizes the μ-using efficiency of each of the wheels, in the case of achieving target vehicle body resultant force and yaw moment in a vehicle motion (patent document 1). In this case, reference symbol k denotes a friction coefficient between a tire and a road surface. In this prior art, under a constraint condition that the μ-using efficiency in each of the wheels is equalized, a tire generating force direction in each of the wheels in which the μ-using efficiency becomes minimum is derived in accordance with a repeated computation of a pseudo-inverse matrix.
In the prior art mentioned above, an optimum solution (a solution minimizing the μ-using efficiency) under the constraint condition that the μ-using efficiency in each of the wheels is equalized coincides with a solution minimizing a maximum value of the μ-using efficiency in each of the wheels in many cases.    Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2004-249971